Particularly in Patent Document 1, a sliding bearing is proposed which is comprised of an upper casing formed of a synthetic resin and having a vehicle body-side seat surface for a vehicle body side and an annular lower surface; a lower casing which is formed of a synthetic resin, is superposed on the upper casing so as to be rotatable about the axis of the upper casing, and has an annular upper surface opposed to the annular lower surface of the upper casing; and an annular thrust sliding bearing piece which is formed of a synthetic resin, and is interposed between the annular lower surface and the annular upper surface, wherein a spring seat surface for a suspension coil spring is integrally formed on a portion of the lower casing on an outer peripheral side of the vehicle body-side seat surface and the thrust sliding bearing piece. According to such a sliding bearing, since the spring seat surface for the suspension coil spring is provided on the lower surface, it is possible to dispense with a spring seat member made of sheet metal.